Did you buy ur A3000 used?
It probably already had them replaced.
Yes, you just unplug the old chip and plug in the new one. If you can plug in one of those A3000 RAM chips then you can totally replace U202, U203.
No desoldering. No soldering. No electrical engineering degree required. You don't even have to have your kid do it for you.
I never replaced a U701 or U714 but I assume they are exactly the same shape and size.
The hardest part is getting your A3000 apart and back together without slicing your hand open or yelling out any naughty words. 
I bought one of them new in the early 90's so I know that one isn't done, at least I don't remember.
The other I bought from an Amiga club member from back in the day.
I do have 4 other 3k's all in the need of love, perhaps they might have them. How would I tell if I have a new gal appose to the pal?
I enjoy taking them down. It take a little patience but, I don't mind... I curse mainly from bending legs when I pull chips...
